The weapon fires 10 pellets at a time every 0.6 seconds and can deliver high damage at close range, but has a high damage falloff over distance. Usage and strategies will vary between classes.

As the Engineer's most powerful weapon, players will use it primarily for defending buildings from nearby attackers, checking suspicious players, or for helping a low-level Sentry Gun finish off an enemy. Pyros may use their Shotgun to engage targets outside the range of their Flamethrower or when underwater. Soldiers will often rely on the Shotgun if they are out of rockets, cannot take the time to reload, and for closed spaces where explosions would cause self-damage. On the other hand, Heavies will employ the Shotgun where there is no time to use the Minigun effectively, or when mobility while firing is most crucial.

Like the Scattergun, Shortstop, and the Force-A-Nature, the Shotgun's first shell will fire at least one pellet straight down the crosshair before "bullet spread" takes effect. When random spread is disabled, the pellets will land forming a three by three grid pattern.

Taunting as Pyro with the Shotgun equipped will perform the Hadouken kill taunt.

Bugs

Sometimes the player will get stuck on the reloading animation in world view while playing as a Soldier. This can be fixed by switching to either primary or melee weapon.

Trivia

Interestingly, when equipping the Shotgun, the Pyro pulls back once on the pump as if ejecting a spent shell, while the Engineer, Soldier, and Heavy do not. This may result from the fact that the game files indicate that there are separate Shotguns for each class that equips one.

The Shotgun appears to be a Winchester Model 12 Trench Gun with an altered stock. This is an American-made firearm, known for its extended use by the Marine Corps when taking Japanese-controlled islands during World War II.

The Shotgun's design also appears to be resembled to a heavily modified 1960s Remington Model 870

The Shotgun is set up as a "Left-Handed" model (as shown by the ejection port being visible on the left hand side of the gun) instead of the vastly more common "Right-Handed" set-up, where the ejection port would be found on the opposite side.

Curiously enough, the Shotgun ejects shells from the right side of the model where there is no ejection port present.

A Shotgun-wielding class cannot pick up a Shotgun that was dropped by a different class.